Fermion - The Java coremodding library for Forge 1.14+

As you may probably be aware, with Minecraft 1.13 Forge took the opportunity to rewrite itself. In this rewrite, the possibility for Java coremods to exist was almost completely removed, opting for a JS-based attempt instead. What Fermion aims to do is bring back what was the old Java-based coremodding, but on a safer level, trying to avoid class loading issues and relying on the Visitor pattern instead of the ClassNode one.

For the User

If you download this mod alone, nothing in your game will change, apart from having three more mod entries in your list. This mod is in fact a library that is meant for developers usage. As soon as you will have a Launch Plugin installed (or, more probably, a mod that has a Launch Plugin), Fermion will activate.

For the Developer

This mod acts as a back-end service that allows you to create Launch Plugins without having to rely on the internals of ModLauncher or Forge. You can refer to the Wiki available on GitHub for a quick start guide on how to create a Launch Plugin for your mod.

Main advantages

• Stable API and Prefab Collection that will be compatible across Minecraft versions: this means that you won't have to update your coremod structure in case something changes in ModLauncher, unless the bytecode of the methods you are editing does.
• Configuration system: all transformers may be enabled or disabled by the user, but they can also provide custom configuration to tailor the experience according to the user needs.
• Proper IDE support: unless you have a JS plugin in your IDE, the new coremod system doesn't provide syntax highlighting or automatic completion. Launch Plugins are written in Java, so now you can.
• Descriptors for Targets: you won't have to classload a class to refer to it, or rely only on method names to target the correct one; you can use Class-, Method-, and FieldDescriptors to do your job quicker.
• Launch Plugin and mod in the same file without having to extract the Launch Plugin or the mod JAR from the archive.
• Crash fast: if something is wrong in the creation of the Launch Plugin, the game won't even start up and an error message will be printed in the logs. This will allow you to catch errors automatically.

IMPORTANT NOTE

To ensure that Fermion is loaded correctly by Forge, the system will copy itself at runtime, effectively creating a new JAR file in the mods directory. This is intended to circumvent a restriction in ModLauncher's loading system. It is not a different mod or a malicious attack: feel free to decompile the JAR or confront the extracted one with the original. The generated file will be automatically deleted when Minecraft closes.